Device for annealing workpieces



Jan. 18, 1966 w. E. ENGELHARD DEVICE FOR ANNEALING woRKPIEcEs 3 Sheets-Sheet l Filed OCT.. 29, 1962 FIG.

ATTO R N EY Jan. 18, 1966 w. E. ENGELHARD 3,229,967

DEVICE FOR ANNEALING WORKPIECES Filed oct. 29, 1962 s sheets-sheet 2 FIG. 2

INVENTOR W. E. EN GELH ARD ATTORNEY Jan. 18, 1966 w. E. ENGELHARD 3,229,967

DEVICE FOR ANNEALING' WORKPIECES Filed oct. 29, 1962 s sheets-sheet s FIG. 3

y 48 r7/////// /A 'Imm 11111111 11111111 Irl 111111 INVENTOR W. E.. ENGELHARD ATTORNEY United States Patent O 3,229,967 DEVICE FOR ANNEALING WORKPIECES William E. Engelhard, Apalachin, N.Y. "Temperatm-e Processing Co. Inc., 2,28 River Road, North Arlington, NJ.) i Filed Oct. 29, 1.962, Ser. No. 233,586

6 Claims. (Cl. 266-5) This invention relates to the art of. annealing work; pieces in the opening off a heating member' such as the' opening of a hightemperature furnace, suchas s hown, for example, at'28 inj'imy 'Patent2,744,745fissued May' 8,1956.` The present invention' constitutes Aan important improvement over the said patent; assetjforth below, 'andi illustrated inthe drawings and recited,4 in the claims.' Int-he annealing of Workpieces in such highjteinperature furnaces, the workpieces'are' ushed with a gas such as hydrogen or helium. As metals becomev'increasingly porousj -at higher' temperatures, arcertain amount'of gas diffusion therethrough occurs; it'is importantjtoexclude ambient atmosphere from workpieces beingY annealed and pre'vent back' flow` or 'diffusion of moisture and air, or other unwanted vaporsV or gases, One method of attemptingto do this would be to pump` thefpuried gases over the Workpieces in such 'volumejy andjhgh 'ratei so as te oed. thev workpiece with. rapidly wistenA ga'ses- Another method isV to use lhigh vacuuml to minimize the expense of the, workpieces tofunwanted'gases'`or4 vaporset high temperatures'. This latter increasesv the diticulties of excluding unwanted' gases "and of vobtaining uniform heating or the high speed coating frequentlynecessary at the end of the cooling cycle.

The present invention provides a means` of accomplishing uniform heating in an envelope of pure gas at or near normal atmospheric: pressure, provides a means of using protective gases in minimal amounts 'both for reasons of economy and temperature uniformity, providesV a means of final g'as'purification immediately before it envelopes the work, provides a means ofA baffling the outward ow of said protectiveV gasto flush away and push-back from,- the werkpieees. any unwanted gases and vapors, provides a means whereby said workpieces may be quenched directly in liquid quench mediums with no intermediate exposure to the air.

The invention is useful inl connection with furnaces opening in any, direction.l V

The device of the present. invetltien nr-,Ovides a predetermined path furthe 110W of' "gases from the innermost portion of the devicewthrough an externalseal such as to resist and prevent return flow, the gases being directed iirst overthe workpieces and then through a tortuous path excluding return ow of moisture, oxygen and other impurities. A"further `feature 'offthe invention is to provide a getterf disposed' internally of the deviceA and through which the gas must 'flow prior to bathing the Workpieces, purifying the' gas so applied and assuring clean bright brazjng, hardening, and annealing of the work. It further possible, pursuant to the present invention, to transfer the work and holder from the furnace to a quenching bath without interruption of the worksealing procedure.

In the drawings:

FIG.` 1 is a vertical sectional view, partly fragmentary, of a method and apparatus embodying the invention,

FIGS. 2 vand 3 Iare similar viewsofbther forms' thereof.

stantiallyjclonsed byfa 'cover plate '1 5 which may` con 's t housing 23 and withinthe inner 'casing 21. A'holdelf;

3,229,967 Patented Jan. 18,1966

ice

In thev drawings, an annealinggapparatus 1t). embodyf 0f; @heating member 'silehjasifrnaee 12.. which may.. have heating elements 13`orf the like'toattain desired tenir peratures.' The opening' 1-1 ofstherfurnace may be sub-v o'f two or more parts` antiV which may have an *open g 16 throughjwhich the vent sleeve 1 7,` offthe "deyice: passes.4 `Aigas supply pipe 18l is connected "atv one 'endf to one or: more sources '40, 4 1 of supplyof gas suchwasf hydrogenor helium'u'nder pressure, 'fornse with work-f pieces 'oifj stainless'st'eel, argon' 'or'l titanium ctn. "Ifhe other` end` of thegas V18v may` be secured" asV at :1 9:

by` welding or the like. to 'the top plate 1'ofthe inner-'` casing' '21,' telescopically 'enclosing the parts" 14, The

' lowerY end, 2,2 of 'casing-21 is disposedin, spaced relation to the bottom of the'tubularba'ie housing ZSfbeng'U- shaped in cross "section, casing'V 21 being"` welded orothe'rfv wise secured as at' 24 to the top plate 20,' The work4 parts 14 as` above noted arev positioned'l on thlbale 39 is'positioned onv the llll'pperrnost "of thel parts to treated and has disposed thereiny a, quantity'or lay: er of metallic :or 'mineral wool 25 suchfas silicon'` car? bide, stainless steel wool, asbestos woolfgklassl wool,

" which aslpresentlyV available, 'are heatresistant injtheg v Ul o rder given. The stainless steel wool, is va getter t, th otherl materials mentioned are substantially inert. S- l`1older 39r may' -be of wire meshj orA other construc onto the workpieces from pipe 18 which opens asat 42v interiorly of the inner casing 21j. Thewoo'l mayL be any Vsuitable Agas purifier, such` asstainless steel"wottl,"I or silicon carbide wool with afsprinkling `or layer `of titaLA niuni'or other grains 26 to serve as a getterf for purifying the` gas passing througlithe pipe 158. andprior to the gas flushing the work I4 in'casing 21. Thus, in operation, the gasespumpe'd through the pipe '18 are freed offmoise ture and oxygenY and wash the |:parts'1`4 to be sealed against the ambient atmosphere, flowing, :as'shown by'v the larrow 27, from the lower endy 22l of the inner casing 21 upwardly between said inner casing 21 andthe outer' casing wall 29 of the inner housing. T he Plate 20, pref,- erably also has downwardly extending therefrom the outer w casing wall 29, thereby secured to the pipeA 18 heldl thereby 4i1`1` spaced relation to the bottom of youter'casing 28, so that thegases owing upwardly V'as indicated byjthe arrowV 27 intermediate the inner easing 2,1 andthe housing` 23 'Witl 1 then ow downwardly as indicated' |by the varrow d 27a between the .bane noticing zsan'd the dit@ *yvan 29 of 'the inner housing and thence again npwardlyas inl dicated by the -'arrow 3Q, intermediatew the"'outer hous? ing wall 28 and outer Vwall 29"of"the' inner hous-v ing. The gas then flows through the sealing ring 31'securing to the outer'housing as'at 32 anddi'sposed Iin relation to thev outer housing 28 and.'l c'iover"".plate'47,v (the latter'iswelded to' sleevet 17, as at 48;). Theseal= ingY 31 may contain a suitable sealing agent such as, ciliccn carbide sacd which amcicnc nciscurc and purities would have to initially penetrate to inner casing 21. Contamination by entry of moisture laden and` impurities by continuous V4ring 33`of 4silicon carbide wool or'sandv or otherl material which provides: a restricted passageway which will not permit "thev revers'ref 110W V0f contaminating air er mriurities., While eriablms gas Vto lflow asv indicatedrbyanrows43 and .36"between the pipe 18 and sleeve 17 and thence out of the discharge pipe 37 for burning or discharge into the atmosphere directly or through a bubbing tank 44 for back pressure and indication of flow. The sleeve 17 may be provided with a stu'ing box collar 38 to permit relative smooth sliding movement between the sleeve 17 and the pipe 18.

Pipe 18 and plate 20 may"`be coupled to elevating and lowering mechanisms by conventional means as through brackets 45, 46 for lowering said sleeve 'and pipe in unison or selectively into the opening 11 `and lthen the cover plate 15 may be used 4to substantially closel said opening around thesleeve 17. 0n completion `of the annealing procedure the sleeve v17 and pipe 18 and associated parts may be elevated in unison or separately out of the opening `11 and into a quenching medium. Such movement olf the parts may be achieved without interrupting the continuous flow of gas in accordanc'ewith` the procedure above set -forth and disclosed herein.

The stuffing box collar 38,`as above noted,l enables relative smooth sliding movement between lthe sleeve 17Y and the pipe 18; the sleeve 17 and plate 47,` secured thereto `as at 48, may simply rest on and press against the ring 33,` in which case the brackets 45, 46 may be engaged and the parts elevated and then positioned in a liquid quenching medium; the latter will tend `to cover the parts 28 and associated parts, which are heavier and thus settle first in the quenching tank. The plate 47 and sleeve 17 'are lighter and thus on movement into the liquid in the quenching tank stay above the outer housing 28. The top plate 20 may be elevated to thereby carry the plate 47 therewith by grasping the bracket 45 land moving the parts upwardly. The workV 14 and associated parts, remaining within the quenching medium, will cool uniformly and while completely sealed from the atmosphere by the immersing liquid. Gases are passed through pipe 18 while the parts are removed froni the furnace and deposited into the quenching tank. The outer housing 28 and associated parts may, insteadqofv being deposited into a liquid quenching medium, be simply lifted out of the lfurnace 12 and left suspended in ambient air, preferably while gas is continuously passed through pipe 18 to immerse the parts in the gas. Air may be blown against the outer housing 28 until the latter is brought down to substantially room temperature., Another procedure which may be used is to lift the assembly of outer housing 28 and associlated-parts from the furnace by engaging and elevating brackets 45, 46 and then positioning the parts over the quenching tank; then,by holding vbracket 45 while perrnittingv brackets "46 `to be lowered', the parts 2S, 23, 21 will be immersedfin the quenching medium. Other quenching procedures` may be resorted to in carrying out the invention, the above being exemplary.

In FIG. 2 the cover plate 47 does notf'have a downtur-nedvmarginal edge extending into sealing `ring 33 and may comprise a layer 49 of silicon carbide wool, for example-which is very satisfactory for the purpose, being a -good insulator and standing up well under diverse temperatures. In the FIG. 2 for-m of the invention the gases may pass out of the outer .housing y28 as at 50, Where they ywill (due to the furnace heat) burn or they may escape to the atmosphere. In the FIG. 2 construction the cover plate 47 is proportioned to lit within the upper edge of the outer housing, leaving a very slight space for escape of gases; this form of invention is adapted for use lwhere the atmosphere can tolerate the 7 The FIG. '3 form'isgenernallyl similar to the FIG.-

2 form in the parts that are correspondingly numbered, 4but in FIG. 3 the work may be positioned on the bottom of the U-shaped housing 23 or on the `bottom of an innermost bale housing 52, positioned inturn on the bottom of the housing 23, and the gas supply pipe 18 is extended so as to terminate on or in the gas purifying device 54, the work in turn being positioned on the device 54 instead of the reverse arrangement shown in FIGS. 1 and 2. The gas passes through the pipe 18, through purifier 54 and thence` upwardly `as at 55, over the top of the innermost housing 52`and downwardly between housing'52 and inner casing 21 and thence ulti-` mately out as at 50. The parts in FIG. 3 corresponding to those of FIGS. l and 2 .are correspondingly numbered.

The cover plate 47 and ,the sleeve 17 press down on the sealing ring 49 to compress the latter between plate 47' and `top plate .20 and essentially seal the latterand the outer casing 28,. y f

Having thus described my invention, what I claimas new and desire to secure by Letters Patent is:

1. A device for annealing workpiecesin a furnace un-y der a selected gaseous medium without exposing them to atmosphere, comprising z' (a) a continuous wall outer housing of uniform crosssection disposed in said furnace and which has one (d) a vent sleeve rigidly connected to said cover plate and which extends up and out of said furnace;

, (e) an innervhousing within said outer housing which has an inner casing and an outer casing, `both of similar cross-section, saidcasings being continuous closed walls concentrically disposed in spaced rela- Y tion to each other;

(f) both said inner casing and said outer casing being open atthe same one end and the other endsthereof being closed by an inner` housing top plate which is t integral therewith and is slightly spaced from said',

cover plate; v (g) the outer casing of said inner housingk being spaced a small distance from Vsaid outer housing and the inner casing of said inner housing enclosing a workpiece positioned therein; (h) a gas supply pipe in said vent sleeve which extends down into said inner housing through said inner housf t ing top plate and to'which it is rigidly connected;

(i) said inner housing'walls at their open end being spaced from said closed end of said outerhousing; (j) an intermediate closed wall bale housing disposed between said concentric spaced' walls of said inner housing in spaced relation thereto andhaving one t end in engagement withsaid closed endof said outerl housing wall and having` its other end open and,`

spaced from said top plate, all of said walls thereby forming a tortuouspath forflow of gas from the interior to the exterior of said inner housing and;

(k) a purifying filter integrally connected with said 1 inner wall of saidinner housing and disposed be tween said gas supply pipe and said workpiece so that all gas must pass from said gas supply pipe and through said filter before reaching said workpiece. 2. A device for annealing Workpieces as setforth in claim 1, wherein: y A;

(a) lift engaging means is provided on said outerhousing for lifting said device from said furnace.4

3. A device for annealing workpieces as set forth in claim 2, wherein:

5 6 (a) lift engaging means is provided on said gas supply- References Cited by the Examiner ing means for lifting only said gas means, said inner UNITED STATES PATENTS housing, and said top plate from said furnace.q 2,152,154 3/1939 Robiette 14g 20 3 4. In a device as set forth in claim 1, said purifying 2,744,745 5/1956 Engdhard 266..-5 lter comprising silicon carbide Wool. 5 3,012,591 12/ 1961 McCormack et al. 148-16 X 5. In a device as set forth in claim 1, said purifying FOREIGN PATENTS filter comprising steel Wool and metallic particles.

6. In a device as set forth in claim 5, said particles comprising grains selected from the following group or a 10 JOHN F- CAMPBELL, Primal? Examinercombination thereof: titanium, silicon, aluminum. JAMES H. TAYMAN, JR., MORRIS WOLK, Examiners.

502,543 3/ 1939 Great Britain. 

1. A DEVICE FOR ANNEALING WORKPIECES IN A FURNACE UNDER A SELECTED GASEOUS MEDIUM WITHOUT EXPOSING THEM TO ATMOSPHERE, COMPRISING: (A) A CONTINUOUS WALL OUTER HOUSING OF UNIFORM CROSSSECTION DISPOSED IN SAID FURNACE AND WHICH HAS ONE CLOSED END AND ONE OPEN END; (B) A COVER PLATE WHICH IS FITTED OVER SAID OPEN END OF SAID OUTER HOUSING AND HAS A PERIPHERY SLIGHTLY SPACED FROM THE WALL OF SAID OUTER HOUSING; (C) A SEALING MEDIUM INTERPOSED BETWEEN THE OUTER HOUSING ADJACENT SAID ONE OPEN END AND THE PERIPHERY OF SAID COVER PLATE; (D) A VENT SLEEVE RIGIDLY CONNECTED TO SAID COVER PLATE AND WHICH EXTENDS UP AND OUT OF SAID FURNACE; (E) AN INNER HOUSING WITHIN SAID OUTER HOUSING WHICH HAS AN INNER CASING AND AN OUTER CASING, BOTH OF SIMILAR CROSS-SECTION, SAID CASINGS BEING CONTINUOUS CLOSED WALLS CONCENTRICALLY DISPOSED IN SPACED RELATION TO EACH OTHER; (F) BOTH SAID INNER CASING AND SAID OUTER CASING BEING OPEN AT THE SAME ONE END AND THE OTHER ENDS THEREOF BEING CLOSED BY AN INNER HOUSING TOP PLATE WHICH IS INTEGRAL THEREWITH AND IS SLIGHTLY SPACED FROM SAID COVER PLATE; (G) THE OUTER CASING OF SAID INNER HOUSING BEING SPACED A SMALL DISTANCE FROM SAID OUTER HOUSING AND THE INNER CASING OF SAID INNER HOUSING ENCLOSING A WORKPIECE POSITIONED THEREIN; (H) A GAS SUPPLY PIPE IN SAID VENT SLEEVE WHICH EXTENDS DOWN INTO SAID INNER HOUSING THROUGH SAID INNER HOUSING TOP PLATE AND TO WHICH IT IS RIGIDLY CONNECTED; (I) SAID INNER HOUSING WALLS AT THEIR OPEN END BEING SPACED FROM SAID CLOSED END OF SAID OUTER HOUSING; (J) AN INTERMEDIATE CLOSED WALL BAFFLE HOUSING DISPOSED BETWEEN SAID CONCENTRIC SPACED WALLS OF SAID INNER HOUSING IN SPACED RELATION THERETO AND HAVING ONE END IN ENGAGEMENT WITH SAID CLOSED END OF SAID OUTER HOUSING WALL AND HAVING ITS OTHER END OPEN AND SPACED FROM SAID TOP PLATE, ALL OF SAID WALLS THEREBY FORMING A TORTUOUS PATH FOR FLOW OF GASS FROM THE INTERIOR TO THE EXTERIOR OF SAID INNER HOUSING AND; (K) A PURIFYING FILTER INTEGRALLY CONNECTED WITH SAID INNER WALL OF SAID INNER HOUSING AND DISPOSED BETWEEN SAID GASS SUPPLY PIPE AND SAID GAS SUPPLY PIPE AND THAT ALL GAS MUST PASS FROM SAID GAS SUPPLY PIPE AND THROUGH SAID FILTER BEFORE REACHING SAID WORKPIECE. 